中国主要湖泊演变趋势及成因分析

湖泊是淡水生态系统的主要组成,系统全面地摸清我国湖泊演变情况,对于动态掌握湖泊资源本底台账,科学有序推进湖泊治理修复,具有重要意义。结合最新有关基础调查工作,对近60 a来中国主要湖泊分布特征、演变趋势及成因进行系统分析。结果表明:近60 a来,我国主要湖泊演变趋势发生较大变化。1956—1979年时段至1980—2000年时段,湖泊萎缩趋势比较明显;1980—2000年时段至2001—2016年时段,萎缩趋势得到逐步扭转;以2000年为分界点,湖泊萎缩态势由部分湖泊大面积萎缩向众多中小湖泊小面积萎缩转变,面积增加湖泊分布从以东北地区为主逐渐向西南和东部地区为主转变。泥沙淤积、围湖造田等是导致湖泊萎缩的主要影响因素;天然来水增加、生态补水实施、生态空间恢复等是2000年之后湖泊空间恢复的主要原因。

Trend and Causes of the Evolution of Major Lakes in China

Lakes are the major components of freshwater ecosystem. Building up a systematic and comprehensive picture of the evolution trend of lakes in China is of crucial significance for a dynamic understanding of the background account of lake resources and a scientific and orderly restoration of lakes. The distribution characteristics as well as the trends and causes of the evolution of major lakes in China over the past six decades were systematically examined based on fundamental surveys. Results revealed a remarkable change of major lakes in China in the past six decades. In the period between 1956-1979 and 1980-2000, the lakes shrank obviously, while between 1956-1979 and 1980-2000, such shrinking trend was gradually reversed. With year 2000 as the turning point, the lakes witnessed a tranform from large-scale shrinking of some lakes to small-scale shrinking of many small and medium-sized lakes; the increasing area of lakes gradually altered from the northeast region to the southwest and eastern regions. Sediment deposition and lake reclamation are main factors leading to lake shrinkage. The increase of natural inflow, the ecological replenishment and the restoration of ecological space are major reasons for the restoration of lake space after 2000.